29 replies to this topic

[HARBER07]

Most efficient way is to fit an engine with 120hp already

[Turbo Phil]

With, say, 120 bhp you do need the improved drive shafts, a cross-pin diff and a gearbox in really good condition. I would not go to SC drops as they are simply too noisy for the road and helicals are OK anyway. It's normally the diff, shafts and CV joints which fail with ultra-high power output.

Got to disagree with this. I know of very few people using uprated driveshafts, & they very rarely, if ever fail, the same for the CV's. A crosspin diff is essential, yes, & imo so are SC drops if you're looking for 120+hp & the associated torque from the Turbo.
When you price up the parts required for a reliable 120hp NA motor that will be nowhere as near as street useable as a decent Turbo motor, I'd say the Turbo route was a quite cost effective method of gaining 120hp & road manners.

Edited by Turbo Phil, 15 May 2010 - 12:07 PM.

[Carlzilla]

main reason ive decided to go turbo on the motor, rather than going n/a

thanks for the input guys

[1293sleeper]

one thing straight cut drop are no stronger than normal drops i have been reading up on this the on reason to go straight cut is to make it cheaper to have a selection of different ratios. they give little to no gain in strengh.

[liirge]

one thing straight cut drop are no stronger than normal drops i have been reading up on this the on reason to go straight cut is to make it cheaper to have a selection of different ratios. they give little to no gain in strengh.

Urrm, going to have to disagree with you on this one i'm afraid, in terms of Straight cut vs Helical gears it is debatable if S\C are stronger however that's not the reason for why you would you use them on a higher power car. Straight Cut gears reduce side loading on the gears. So if there is less side loading then, the bearings are going to be under less stress and should last longer, as well as the gear itself, this is essential on the drop gears.
The ratio argument is actually for S\C gear sets and not really Drops, if im right i believe that BL or Rover, only produced one variation on the drop gears, and that was the economy sets for the City E models (model could be incorrect).

Edited by liirge, 16 May 2010 - 11:21 AM.

[mymini007]

Surely if you are going to be running 120bhp, you need to uprate everything, pistons, con-rods, crank, its not just a case of slapping a turbo on and away you go.

I Spoke to Hythe performance, minispeed and a couple of chaps with big power engines and all have said that the above are all 100% essential, so I think the full set up for 120 bhp unit from mini speed worked out to be about £3500. Thats why I didn't bother.

But I may be wrong

[rick.spi]

certain bits will need to be uprated, but some may not. condition comes into play alot there.

standard conrods are ok, and a standard crank in good condition will be ok as long as your not revving it too much. a 120bhp turbo lump wont have all the power at the top and will have alot of it after around 3k rpm (t3) so you wont need to rev the turbo lump as much as much as a NA 120 bhp motor where in most cases will be very highly revving highly cammed machines, thats where you need the uprated rods etc and crank etc. and 120bhp isnt too hard to acheive with a good condition turbo lump.

i payed around £2800 for my turbo engine build and i would say thats a good spec. so i dont know how the £3500 120bhp unit from minispeed works out unless he is on about a NA lump.

[huw_jenks]

Nitrous Oxide anyone?

[Carlzilla]

cost i dont mind, as it will be done over a peroid of time, isnt a case of i dont have an engine get the thing in the car quickly sorta thing.

just need to get myself a good extensive list of parts together now and get ready to start purchasing, starting with a good condition 1275

[Turbo Nick]

Surely if you are going to be running 120bhp, you need to uprate everything, pistons, con-rods, crank, its not just a case of slapping a turbo on and away you go.

I Spoke to Hythe performance, minispeed and a couple of chaps with big power engines and all have said that the above are all 100% essential, so I think the full set up for 120 bhp unit from mini speed worked out to be about £3500. Thats why I didn't bother.

But I may be wrong

you would be correct in thinking you're wrong

I'm running a shade under 200hp on the exact same engine i built years ago as a 120hp build, std rods, std crank, AE cast pistons etc...

[Carlzilla]

just had a glance through your project build bud, damn you i shoulda been in bed an hour ago as it was lol.

cant be far away from me i guess as you know pauly and are from the black countraaaay

fancy drawing me up a list of things im going to need please?

[Turbo Nick]

this any good for you?

http://www.bud666.pw...conversion.html

probably not too far away, if you see a nato green VW T4 van driving around thats me, lol.

[Carlzilla]

thanks mate, that should do me

just booked my 998 into aldon for a rolling road session to get it going a bit better, hopefully itll make a big difference to it, and keep me going for longer with less worrying its gonna conk out

[Turbo Phil]

As stated above, it's not the most expensive parts that will build a reliable engine it's attention to detail & correct build. As most Turbo engines are not high revving compared to high power NA engines you don't need an all singing & dancing crank & rods.
Like Bud I'm using cast pistons & a standard crank, my car has been running a minimum of 15psi for the last two years. Do some research, buy your parts wisely & build it yourself or get somebody knowledgable to help & you'll be able to build it far cheaper than the big companies will sell you an engine for.

[1293sleeper]

plus turbo is a cheaper way to get that kinda power im aiming for similar power but have gone the N/A route and have spent close to £3k on my engine alone and that is a self build and i had alot of the parts already.
but it has
low friction pistons, vmax skart lightend polished con rods, lightened ballanced crank, lightened fly wheel, longman race head, kent 286 cam,1-3 roller rockers, megajolt ignition, high output oil pump, cam belt convertion, refurb gearbox .
The block has been reboard with all new bearings including cam bearings. (soon to have nitro too)
the engine i know will bw a totall pain to drive in town and traffic but as soon as i hit the open road its going to be amazing

Edited by 1293sleeper, 18 May 2010 - 10:09 PM.